Non-constrained total joint system

A non-constrained total joint system for effecting an articulation between first and second adjacent resected bony shafts, the system comprising:

• a first component composed of a unitary, non-plastic biocompatible material and formed as an integral head and rearwardly projecting first stem, said first stem configured to be received in the end of said first bony shaft, said head having a convex bearing surface having a large major radius of curvature relative to a diameter of said head and approximating that of the anatomic articulating surface and extending up to 180.degree., said head further having a non-bearing intermediate portion interposed between said first stem and said convex bearing surface to offset said convex bearing surface from the end of said first bony shaft by a distance which provides sufficient clearance for articulation of the joint system and protecting said convex bearing surface against possible boney overgrowth;
• a second component, including an integral receptacle portion and a rearwardly projecting second stem, said second stem configured to be received in the end of said second bony shaft, said receptacle portion being substantially cylindrically shaped with an outer first beveled surface and receiving an intermediate insert formed of a biocompatible plastic, fixedly disposed within said receptacle portion, said insert including a concave bearing surface conforming to said convex bearing surface and of an area significantly less than the area of said convex bearing surface, said intermediate insert projecting beyond said receptacle portion and having a second beveled surface intersecting with said concave bearing surface and substantially forming an extension of said first beveled surface and protecting said concave bearing surface against possible boney overgrowth.

A non-constrained total joint system for effecting an articulation between first and second adjacent resected bony shafts, the system comprising:

• a first component composed of a unitary, non-plastic biocompatible material and formed as an integral first head and rearwardly projecting first stem, said first stem configured to be received in the end of said first bony shaft, said head having a convex bearing surface having a large major radius of curvature relative to a diameter of said head and approximating that of the anatomic articulating surface and extending up to 180.degree., said head further having a non-bearing intermediate portion interposed between said first stem and said convex bearing surface to offset said convex bearing surface from the end of said first bony shaft by a distance which provides sufficient clearance for articulation of the joint system and protecting said convex bearing surface against possible boney overgrowth;
• a second component, including a second head attached to a rearwardly projecting second stem, said second stem configured to be received in the end of said second bony shaft, said second head being substantially cylindrically shaped with an outer beveled surface, said second head including a concave bearing surface formed of a biocompatible plastic conforming to said convex bearing surface and of an area significantly less than the area of said convex bearing surface, said beveled surface intersecting with said concave bearing surface and protecting said concave bearing surface against possible boney overgrowth.